Ever since Pluto was demoted to the status of a “dwarf planet” — or a plutoid to be specific, in reference to any trans-Neptunian dwarf planet — thanks to some sly redrawing of the definition of a planet, it has been a constant source of amazement. Back in 2006, an IAU meet decided that to be a planet, the body in question would have to keep its orbit clear. The relatively large mass of, say the Earth, Mars or Jupiter, mean they engulf or push away anything in their orbit, but Pluto’s orbit was filled by stray objects, some of which were almost comparable in size to Pluto itself. And then there was also the discovery of the dwarf planet now known as “Eris”, which was a good example of there being objects in the Kuiper belt outlining the solar system that have sizes as big as, if not bigger than, our dear Pluto.
Thanks to the flyby of New Horizons, we managed to accumulate an incredible lot of data that has been dumbfounding us with its revelations about Pluto. Just last week the strange question of the presence of a reddish material all over the poles of Charon, Pluto’s natural satellite, was answered with some certainty. “Pluto is a graffiti artist”, as New Horizons co-investigator, Will Grundy colourfully put it. It is believed that methane escapes from Pluto only to be trapped by Charon’s gravitational pull — the moon is 12% the mass of its host planet — where it freezes. Continue reading